Yes, as Bangkokboy said, "dix" is pronounced "dees" in French. 
As for Windows XP, I don't think it works because the S of Windows is pronounced Z. So it would be moer like "Windows Zex Pee".
Anyway, it's not all that important, I was just wondering what was the right way to pronounce OS X, it seems there is no concensus, so I'll just keep on calling it OS Ten (I prefer that).
And Bangkokboy, that was funny... But maybe you shouldn't speak, huh?
